Primary osteosarcoma of the skull

Case Report Australasian Radiology (2006) 50, 63–65 Primary osteosarcoma of the skull F Haque,1 ST Fazal,1 SA Ahmad,1 SZ Abbas1 and S Naseem2 Departments of 1Radiodiagnosis and 2Pathology, Jawahar Lal Nehru Medical College, Aligarh Muslim University, Aligarh, India SUMMARY Primary osteogenic sarcoma of the skull is an exceedingly rare condition. An adult male patient is described, who had a painless swelling in the right forehead that had rapidly enlarged in the previous 6 months. Radiological investigations showed a large destructive mass lesion involving the right side of the frontal bone with extension into the frontal sinus, causing marked extradural compression of brain parenchyma. Histopathological examination confirmed the lesion to be primary osteogenic sarcoma. Key words: chondrosarcoma; frontal bone; primary osteogenic sarcoma; skull. INTRODUCTION the frontal sinus, also involving the greater wing of sphenoid. The Osteogenic sarcoma is the second most common primary soft tissue density mass had a few bony densities within and malignant tumour of bone, after multiple myeloma, and is highly showed intense enhancement on i.v. contrast administration, aggressive in nature.1–4 Osteosarcoma of the calvarium is a rare with marked extradural compression of brain parenchyma. condition. It may present in the later decades of life, but is Bone scanning showed no evidence of a mass lesion at any mostly secondary, associated with pre-existing benign diseases other site. Chest radiography showed no evidence of distant (Paget disease, fibrous dysplasia and bone infarct) or previous metastases. Primary intracranial osteosarcoma and chondro- irradiation. Primary osteogenic sarcoma of the skull is an exceed- sarcoma were considered as preoperative differential diagnoses. ingly rare presentation. Cases have been reported both in youn- Frontal craniotomy was carried out with radical resection of the ger persons and in adults.1 We present a case of primary tumour with a large margin of normal bone. Histopathological osteogenic sarcoma of the frontal bone in a patient in his sev- examination showed osteoblastic osteosarcoma (Fig. 2). Sur- enth decade. gical margins were free of tumour cells, with normal brain parenchyma. The patient did not have subsequent chemother- CASE REPORT apy or radiotherapy. A 60-year-old male patient had a painless swelling in the right forehead that had rapidly enlarged in the previous 6 months. DISCUSSION There was no history of trauma. A firm, nontender mass was Osteosarcoma is a primary and the only malignant tumour noted on physical examination. On neurological examination, derived from bone, arising from undifferentiated connective tis- no focal motor or sensory deficit was seen. Higher mental func- sue within bone forming neoplastic osteoid and osseous tissues tions were assessed as normal. Radiographic evaluation of the during the course of its evolution.2 It is primarily a disease of the patient was carried out, which included plain skull radiography long bones, with greatest predilection for the metaphysis, pref- and cranial CT. Plain skull radiograph showed an expansile erably around the knee joint. These tumours mainly occur in the destructive lesion of the right side of frontal bone. Computed younger age group, with 75–80% of patients of age between 10 tomography (Fig. 1) showed a large destructive mass lesion and 25 years. Men are slightly more susceptible, the male:female involving the right side of the frontal bone with extension into ratio being 3:2.1 A secondary peak in incidence of osteosarcoma F Haque MD; ST Fazal MD; SA Ahmad MD; SZ Abbas MD; S Naseem MD. Correspondence: Dr Faisal Haque, 41-Alig Appartment, Shamshad Market, Aligarh 202002, India. Email: faisalhaque1@rediffmail.com Submitted 25 August 2004; accepted 07 February 2005. doi: 10.1111/j.1440-1673.2005.01537.x ª 2006 Royal Australian and New Zealand College of Radiologists F HAQUE ET AL. 64 Fig. 1. (a,b) Contrast-enhanced CT of skull: large expansile destructive lesion involving the right side of frontal bone with intense contrast enhancement in the associated soft tissue with marked extradural compression. is seen over the age of 60 years in association with pre-existing those seen in long bones, such as osteolytic, osteoblastic or benign diseases or previous irradiation, with a predilection for mixed lesions with an aggressive periosteal reaction (lamin- flat bones. ated, sunburst or Codman’s triangle) and a large soft tissue Approximately 6% of osteosarcomas occur in the head and component.4 Cranial CT shows similar changes to those seen neck region, with the majority occurring in the mandible. Pri- in extremities. Computed tomography is useful in determining mary involvement of the cranial vault, excluding the mandible the intraosseous extent of an osteosarcoma and in showing the and maxilla, is an exceedingly rare phenomenon. Nora et al. presence of prominent new bone formation in the soft tissue have reported only 21 cases of primary cranial vault osteosar- component. Computed tomography is superior to plain films in coma among more than 1000 cases studied.3 Caron et al. listed the evaluation of the extraosseous extent and for staging and 11 cases of calvarial osteosarcoma during their 37-year study.4 defining the extent of surgical resection. Magnetic resonance is Most patients with calvarial osteosarcoma have certain predis- superior to CT in showing the soft tissue extent of the tumour. posing conditions such as Paget disease or previous irradiation,1 Other radiological methods also play a role in the evaluation of with fibrous dysplasia, multiple osteochondromatosis, osteomy- patients with suspected calvarial osteogenic sarcoma. Radio- elitis and myositis ossificans accounting for other predisposing isotope bone scanning, although non-specific, shows acceler- factors.3,5 Very few cases of osteosarcomas of the skull occur ated osteogenic activity of any aetiology. It is useful in showing as a primary development. unsuspected polyostotic involvement. Angiography is useful in The most common presenting complaint is localized swell- defining the soft tissue extent of the tumour and involvement of ing, usually without associated pain at first. Plain skull radio- major vessels by it. Tumour blood supply from the cortical graphs in calvarial osteosarcoma show similar bony changes to branches of the internal carotid artery, for example, probably indicates tumour invasion beyond the dura. The differential diagnosis of cranial osteosarcoma to be considered includes chondrosarcoma and osteochondroma. The CT findings of new bone formation in the soft tissue mass and the characteristic matrix strongly suggest osteogenic sarcoma, but differentiation from chondrosarcoma and osteochondroma cannot be made definitely without histology. Computed tomography in cases of chondrosarcoma of the base of skull shows similar changes, but once the calvarium undergoes membranous ossification, it becomes an unlikely site for cartilaginous tumours.5 Osteochondromas usually are sharply defined and homogenous in density.6 The treatment of calvarial osteosarcoma may be complex. Complete excision of the tumour with clear margins is the current treatment of choice.3,7,8 In cases where radical surgery is Fig. 2. Conventional osteosarcoma showing spindle cells, giant cells and osteoid matrix. not possible, incomplete excision of the tumour with adjuvant chemotherapy and radiotherapy is suggested, but they are ª 2006 Royal Australian and New Zealand College of Radiologists PRIMARY OSTEOSARCOMA OF SKULL palliative.1 Distant metastases, for example to lung, occur 65 3. rarely.8 The prognosis of cranial osteosarcomas is less favourable than for those occurring in long bones.1 Local recurrence of the tumour is the most significant factor contributing to poor 4. 5. outcome.7 The 5-year survival rate is approximately 10%.3,4 6. REFERENCES 1. 2. Benson JE, Goske M, Han JS, Brodkey JS, Yoon YS. Primary osteogenic sarcoma of the calvaria. AJNR 1984; 5: 810–13. Cade S. Osteogenic sarcoma: study based on 133 patients. J R Coll Surg Edinb 1955; 1: 79–111. 7. 8. ª 2006 Royal Australian and New Zealand College of Radiologists Nora FE, Unni KK, Pritchard DJ, Dahlin DC. Osteosarcoma of extragnathic craniofacial bones. Mayo Clin Proc 1983; 58: 268–72. Caron AS, Hajdu SI, Strong EW. Osteogenic sarcoma of the facial and cranial bones. Am J Surg 1971; 122: 719–25. Vandenberg HJ Jr, Coley BL. Primary tumours of the cranial bones. Surg Gynecol Obstet 1950; 90: 602–12. Rao VRK, Rout D, Radhakrishnan V. Osteogenic sarcoma of the skull. Neuroradiology 1983; 25: 51–3. Kanazawa R, Yoshida D, Takahashi H. Osteosarcoma arising from the skull case report. Neurol Med Chir 2003; 43: 88–91. Shinoda J, Kumura T, Funakoshi T. Primary osteosarcoma of the skull—a case report and review of the literature. J Neurooncol 1993; 17: 81–8.